pragma solidity ^0.4.8;

// ----------------------------------------------------------------------------------------------
// The Waves Community token smart contract - to find out more, join the Incent Slack; http://incentinvites.herokuapp.com/
// A collaboration between Incent and Bok :)
// Enjoy. (c) Incent Loyalty Pty Ltd and Bok Consulting Pty Ltd 2017. The MIT Licence.
// ----------------------------------------------------------------------------------------------

// Contract configuration
contract TokenConfig {
    string public constant symbol = "WBTC";
    string public constant name = "Waves Bitcoin Token";
    uint8 public constant decimals = 8;  // 8 decimal places, the same as tokens on Wave
    uint256 _totalSupply = 2100000000000000;
}

// ERC Token Standard #20 Interface
// https://github.com/ethereum/EIPs/issues/20
contract ERC20Interface {
    // Get the total token supply
    function totalSupply() constant returns (uint256 totalSupply);

    // Get the account balance of another account with address _owner
    function balanceOf(address _owner) constant returns (uint256 balance);

    // Send _value amount of tokens to address _to
    function transfer(address _to, uint256 _value) returns (bool success);

    // Send _value amount of tokens from address _from to address _to
    function transferFrom(address _from, address _to, uint256 _value) returns (bool success);

    // Allow _spender to withdraw from your account, multiple times, up to the _value amount.
    // If this function is called again it overwrites the current allowance with _value.
    // this function is required for some DEX functionality
    function approve(address _spender, uint256 _value) returns (bool success);

    // Returns the amount which _spender is still allowed to withdraw from _owner
    function allowance(address _owner, address _spender) constant returns (uint256 remaining);

    // Triggered when tokens are transferred.
    event Transfer(address indexed _from, address indexed _to, uint256 _value);

    // Triggered whenever approve(address _spender, uint256 _value) is called.
    event Approval(address indexed _owner, address indexed _spender, uint256 _value);
}

contract WavesBitcoinToken is ERC20Interface, TokenConfig {
    // Owner of this contract
    address public owner;

    // Balances for each account
    mapping(address => uint256) balances;

    // Owner of account approves the transfer of an amount to another account
    mapping(address => mapping (address => uint256)) allowed;

    // Functions with this modifier can only be executed by the owner
    modifier onlyOwner() {
        if (msg.sender != owner) {
            throw;
        }
        _;
    }

    // Constructor
    function WavesBitcoinToken() {
        owner = msg.sender;
        balances[owner] = _totalSupply;
    }

    function totalSupply() constant returns (uint256 totalSupply) {
        totalSupply = _totalSupply;
    }

    // What is the balance of a particular account?
    function balanceOf(address _owner) constant returns (uint256 balance) {
        return balances[_owner];
    }

    // Transfer the balance from owner's account to another account
    function transfer(address _to, uint256 _amount) returns (bool success) {
        if (balances[msg.sender] >= _amount
            && _amount > 0
            && balances[_to] + _amount > balances[_to]) {
            balances[msg.sender] -= _amount;
            balances[_to] += _amount;
            Transfer(msg.sender, _to, _amount);
            return true;
        } else {
            return false;
        }
    }

    // Send _value amount of tokens from address _from to address _to
    // The transferFrom method is used for a withdraw workflow, allowing contracts to send
    // tokens on your behalf, for example to "deposit" to a contract address and/or to charge
    // fees in sub-currencies; the command should fail unless the _from account has
    // deliberately authorized the sender of the message via some mechanism; we propose
    // these standardized APIs for approval:
    function transferFrom(
        address _from,
        address _to,
        uint256 _amount
) returns (bool success) {
        if (balances[_from] >= _amount
            && allowed[_from][msg.sender] >= _amount
            && _amount > 0
            && balances[_to] + _amount > balances[_to]) {
            balances[_from] -= _amount;
            allowed[_from][msg.sender] -= _amount;
            balances[_to] += _amount;
            Transfer(_from, _to, _amount);
            return true;
        } else {
            return false;
        }
    }

    // Allow _spender to withdraw from your account, multiple times, up to the _value amount.
    // If this function is called again it overwrites the current allowance with _value.
    function approve(address _spender, uint256 _amount) returns (bool success) {
        allowed[msg.sender][_spender] = _amount;
        Approval(msg.sender, _spender, _amount);
        return true;
    }

    function allowance(address _owner, address _spender) constant returns (uint256 remaining) {
        return allowed[_owner][_spender];
    }
}

contract WavesEthereumSwap is WavesBitcoinToken {
    event WavesTransfer(address indexed _from, string wavesAddress, uint256 amount);

    function moveToWaves(string wavesAddress, uint256 amount) {
        if (!transfer(owner, amount)) throw;
        WavesTransfer(msg.sender, wavesAddress, amount);
    }
}